Color filters are used for liquid crystal displays (LCDs), optical filters for cameras, and the like. Color filters may be fabricated by coating a fine region with three or more colors on a charge-coupled device or a transparent substrate. A colored thin film can be fabricated using methods such as dyeing, printing, electrophoretic deposition (EPD), pigment dispersion, and the like.
The color filter is prepared through many chemical treatments during the manufacturing process. Accordingly, in order to maintain a pattern formed under the aforementioned conditions, a color photosensitive resin is required to have a development margin but chemical resistance and thus to improve yield of a color filter.
Particularly, since a color filter of a liquid crystal display device is formed on a TFT array panel using color filter-on-array (COA) method, a process of forming a transparent electrode on a color filter is needed. The transparent electrode may be fabricated by sequentially forming a transparent conductive layer and a photosensitive resin layer on a color filter, exposing and developing and patterning the photosensitive resin layer, and etching the transparent conductive layer with the use of the patterned photosensitive resin layer. The color filter is required to have chemical resistance because the color filter may be exposed to diverse liquid chemicals, such as a stripping solution for developing the photosensitive resin layer. Also, the color filter is required to have heat resistance because a plurality of heat treatments are required to form the color filter.
Accordingly, there is a need for a color filter that has excellent chemical resistance and heat resistance, and can provide a pixel layer having a high contrast ratio.